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The disease AIDS is the result of infection by the human immunodeficiency virus (HIV), a retrovirus which has RNA as its genetic material - VCE - SSCE Biology - Question 8 - 2006 - Paper 1
Question 8
The disease AIDS is the result of infection by the human immunodeficiency virus (HIV), a retrovirus which has RNA as its genetic material. a. RNA is a nucleic acid,... show full transcript
Worked Solution & Example Answer:The disease AIDS is the result of infection by the human immunodeficiency virus (HIV), a retrovirus which has RNA as its genetic material - VCE - SSCE Biology - Question 8 - 2006 - Paper 1
Step 1
Draw a labelled diagram of a monomer of RNA.
Answer
To draw a labelled diagram of a monomer of RNA, include the following components:
- Phosphate group: Shown as a circle.
- Ribose sugar: Illustrated as a pentagon, connected to the phosphate group.
- Nitrogenous base: Attached to the ribose; the base can be adenine, guanine, cytosine, or uracil. Ensure each part is distinctly labelled and connected correctly.
Step 2
Explain what is happening in the first year after infection with the HIV virus.
Answer
In the first year after infection with the HIV virus, T cell concentrations initially peak as the immune system attempts to respond to the viral infection. However, after about six months, the T cell count declines significantly as the body becomes overwhelmed by the HIV particles. During this period, the concentration of HIV increases, indicating that the virus is multiplying. This reflects the struggle of the immune system to fight off the infection.
Step 3
Explain.
Answer
In the second to fifth years after infection, the patient experiences swollen lymph nodes as a response to the immune system's attempt to combat HIV. The swollen lymph nodes indicate that the immune system is actively engaged in fighting the virus, causing a proliferation of lymphocytes and other immune cells in the lymphatic system. This response is part of the body’s defense mechanism against the persistent HIV infection.